Green Tea Polyphenols, Mimicking the Effects of Dietary Restriction, Ameliorate High-Fat Diet-Induced Kidney Injury via Regulating Autophagy Flux

Xie, Xia; Wu, Yi; Zhang, Piwei; Wu, Nannan; Yan, Qiaoqiao; Yang, Hui; Tian, Chong; Xiang, Siyun; Du, Mingmei; Assefa, Eskedar Getachew; Zuo, Xuezhi; Ying, Chenjiang

doi:10.3390/nu9050497

Cited by 20 publications

(10 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Tea polyphenols may exert antioxidant capacities through the following mechanisms: (1) straightly reducing oxidants; (2) chelating metal ions; (3) transferring hydrogen; (4) scavenging free radicals; (5) improving activities of antioxidant enzymes; (6) increasing contents of endogenous antioxidants; and (7) regulating antioxidant-related genes [4,44,45,46,47,48,49,50,51]. All of these actions lead to the health functions of tea, such as anticancer, cardiovascular protective, neuroprotective, hepatoprotective, and renoprotective effects [6,52,53,54,55,56]. Thus, several teas rich in antioxidants can be developed into functional foods or nutraceuticals to prevent and treat certain oxidative stress-related chronic diseases.…”

Section: Discussionmentioning

confidence: 99%

Phytochemical Composition and Antioxidant Capacity of 30 Chinese Teas

et al. 2019

View full text Add to dashboard Cite

Tea has been reported to prevent and manage many chronic diseases, such as cancer, diabetes, obesity, and cardiovascular diseases, and the antioxidant capacity of tea may be responsible for these health benefits. In this study, the antioxidant capacities of fat-soluble, water-soluble, and bound-insoluble fractions of 30 Chinese teas belonging to six categories, namely green, black, oolong, dark, white, and yellow teas, were systematically evaluated, applying ferric-reducing antioxidant power and Trolox equivalent antioxidant capacity assays. In addition, total phenolic contents of teas were determined by Folin–Ciocalteu method, and the contents of 18 main phytochemical compounds in teas were measured by high-performance liquid chromatography (HPLC). The results found that several teas possessed very strong antioxidant capacity, and caffeine, theaflavine, gallic acid, chlorogenic acid, ellagic acid, and kaempferol-3-O-glucoside, as well as eight catechins, were the main antioxidant compounds in them. Thus, these teas could be good natural sources of dietary antioxidants, and their extracts might be developed as food additives, nutraceuticals, cosmetics, and pharmaceuticals.

show abstract

Section: Discussionmentioning

confidence: 99%

Phytochemical Composition and Antioxidant Capacity of 30 Chinese Teas

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Previous findings of the protective role of autophagy in various kidney diseases have led to the idea that upregulation of autophagy might represent a plausible therapeutic intervention in these disorders. [14][15][16] However, under lipid overload, simple autophagy "activation" may increase lysosomal stress, resulting in more downstream suppression of autophagy. Instead, pharmacologic correction that restores autophagic flux represents a novel therapeutic option.…”

mentioning

confidence: 99%

Proximal Tubule Autophagy Differs in Type 1 and 2 Diabetes

Sakai

Yamamoto

Takabatake

et al. 2019

JASN

View full text Add to dashboard Cite

BackgroundEvidence of a protective role of autophagy in kidney diseases has sparked interest in autophagy as a potential therapeutic strategy. However, understanding how the autophagic process is altered in each disorder is critically important in working toward therapeutic applications.MethodsUsing cultured kidney proximal tubule epithelial cells (PTECs) and diabetic mouse models, we investigated how autophagic activity differs in type 1 versus type 2 diabetic nephropathy. We explored nutrient signals regulating starvation-induced autophagy in PTECs and used autophagy-monitoring mice and PTEC-specific autophagy-deficient knockout mice to examine differences in autophagy status and autophagy’s role in PTECs in streptozotocin (STZ)-treated type 1 and db/db type 2 diabetic nephropathy. We also examined the effects of rapamycin (an inhibitor of mammalian target of rapamycin [mTOR]) on vulnerability to ischemia-reperfusion injury.ResultsAdministering insulin or amino acids, but not glucose, suppressed autophagy by activating mTOR signaling. In db/db mice, autophagy induction was suppressed even under starvation; in STZ-treated mice, autophagy was enhanced even under fed conditions but stagnated under starvation due to lysosomal stress. Using knockout mice with diabetes, we found that, in STZ-treated mice, activated autophagy counteracts mitochondrial damage and fibrosis in the kidneys, whereas in db/db mice, autophagic suppression jeopardizes kidney even in the autophagy-competent state. Rapamycin-induced pharmacologic autophagy produced opposite effects on ischemia-reperfusion injury in STZ-treated and db/db mice.ConclusionsAutophagic activity in PTECs is mainly regulated by insulin. Consequently, autophagic activity differs in types 1 and 2 diabetic nephropathy, which should be considered when developing strategies to treat diabetic nephropathy by modulating autophagy.

show abstract

“…Tea also exhibits some other health functions in vitro and in vivo, as shown in Tables 2 and 3, respectively. For instance, tea could protect against kidney injuries induced by a high-fat diet, proline, gentamicin, lead, and ischemia-reperfusion [178][179][180][181][182][183]. In addition, tea has exhibited the neuro-protective effect, in terms of protecting against age-related neuro-degenerative disorders, depression and regulating the circadian clock [184][185][186][187][188][189][190].…”

Section: Other Health Functionsmentioning

confidence: 99%

Health Functions and Related Molecular Mechanisms of Tea Components: An Update Review

Tang

Meng

Gan

et al. 2019

IJMS

270

150

View full text Add to dashboard Cite

Tea is widely consumed all over the world. Generally, tea is divided into six categories: White, green, yellow, oolong, black, and dark teas, based on the fermentation degree. Tea contains abundant phytochemicals, such as polyphenols, pigments, polysaccharides, alkaloids, free amino acids, and saponins. However, the bioavailability of tea phytochemicals is relatively low. Thus, some novel technologies like nanotechnology have been developed to improve the bioavailability of tea bioactive components and consequently enhance the bioactivity. So far, many studies have demonstrated that tea shows various health functions, such as antioxidant, anti-inflammatory, immuno-regulatory, anticancer, cardiovascular-protective, anti-diabetic, anti-obesity, and hepato-protective effects. Moreover, it is also considered that drinking tea is safe to humans, since reports about the severe adverse effects of tea consumption are rare. In order to provide a better understanding of tea and its health potential, this review summarizes and discusses recent literature on the bioactive components, bioavailability, health functions, and safety issues of tea, with special attention paid to the related molecular mechanisms of tea health functions.

show abstract

Green Tea Polyphenols, Mimicking the Effects of Dietary Restriction, Ameliorate High-Fat Diet-Induced Kidney Injury via Regulating Autophagy Flux

Cited by 20 publications

References 43 publications

Phytochemical Composition and Antioxidant Capacity of 30 Chinese Teas

Phytochemical Composition and Antioxidant Capacity of 30 Chinese Teas

Proximal Tubule Autophagy Differs in Type 1 and 2 Diabetes

Health Functions and Related Molecular Mechanisms of Tea Components: An Update Review

Contact Info

Product

Resources

About